ACAAN...SI by Gianluigi Sordellini

A deck of cards is taken and shuffled repeatedly by the magician. Then, the magician takes a face-up card from another deck and hands it to a spectator, asking them to insert it anywhere in the deck, leaving it halfway out. This card will naturally end up between two cards, which are then extracted and shown as the magician says: "These two cards indicate a number, let’s imagine it's a 3 and a 9, so given there are 52 cards, the only number they can indicate is 39!" Continuing, the deck is spread in a ribbon, and a second spectator is invited to take the same card as the first spectator and insert it anywhere along the ribbon. This card will, again, be placed between two other cards, one of which will indicate the value, and the other the suit. Well, counting 39 cards down in the deck, the thirtyninth card will match the card formed by the second spectator.